Updated on 2025/04/01

写真a

 
MENJO Hiroaki
 
Organization
Institute for Space-Earth Environmental Research Division for Cosmic Ray Research Assistant Professor
Graduate School
Graduate School of Science
Title
Assistant Professor
External link

Degree 1

  1. Doctor (Science) ( 2009.6   Nagoya University ) 

Research Interests 3

  1. Hadronic Interaction

  2. High-Energy Cosmic-ray

  3. Neutrino

Current Research Project and SDGs 3

  1. 高エネルギー宇宙線のためのLHC加速器を用いたハドロン相互作用の研究

  2. Precise estimation of atmospheric neutrino flux

  3. Neutrino study with Super-Kamiokande detector

Research History 4

  1. Nagoya University   Institute for Space-Earth Environmental Research Division for Cosmic Ray Research   Assistant Professor

    2018.6

  2. 名古屋大学リーディング大学院フロンティア宇宙プログラム・特任助教

    2013.3 - 2018.5

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    Country:Japan

  3. Kobayashi Maskawa Institute, Nagoya University. Assistant Professor

    2011.1 - 2013.3

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    Country:Japan

  4. INFN Florence, Post-doctor

    2009.7 - 2010.12

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    Country:Italy

Education 2

  1. Nagoya University   Graduate School, Division of Natural Science

    2005.4 - 2009.6

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    Country: Japan

  2. Nagoya University   Faculty of Science

    1999.4 - 2003.3

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    Country: Japan

Professional Memberships 1

  1. 日本物理学会

 

Papers 91

  1. Measurement of the transverse single-spin asymmetry for forward neutron production in a wide <i>p</i><sub>T </sub>range in polarized <i>p</i> plus <i>p</i> collisions at √<i>s </i>=510 GeV Reviewed International coauthorship International journal

    Kim, MH; Adriani, O; Berti, E; Bonechi, L; D'Alessandro, R; Goto, Y; Hong, B; Itow, Y; Kasahara, K; Kim, Y; Lee, JH; Lee, SH; Ljubicic, T; Menjo, H; Mitsuka, G; Nakagawa, I; Ogawa, A; Oh, S; Sako, T; Sakurai, N; Sato, K; Seidl, R; Tanida, K; Torii, S; Tricomi, A

    PHYSICAL REVIEW D   Vol. 109 ( 1 )   2024.1

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:Physical Review D  

    Transverse single-spin asymmetries AN of forward neutrons at pseudorapidities larger than 6 had only been studied in the transverse momentum range of pT<0.4 GeV/c. The RHICf Collaboration has extended the previous measurements up to 1.0 GeV/c in polarized p+p collisions at s=510 GeV, using an electromagnetic calorimeter installed in the zero-degree area of the STAR detector at the Relativistic Heavy Ion Collider. The resulting AN values increase in magnitude with pT in the high longitudinal momentum fraction xF range, but they reach a plateau at lower pT for lower xF values. For low transverse momenta, the AN's show little xF dependence and level off from intermediate values. For higher transverse momenta, the AN's also show a tendency to reach a plateau at increased magnitudes. The results are consistent with previous measurements at lower collision energies, suggesting no s dependence of the neutron asymmetries. A theoretical model based on the interference of π and a1 exchange between two protons could partially reproduce the current results; however, an additional mechanism is necessary to describe the neutron AN's over the whole kinematic region measured.

    DOI: 10.1103/PhysRevD.109.012003

    Web of Science

    Scopus

  2. Performance of RHICf detector during operation in 2017 Reviewed International coauthorship International journal Open Access

    Adriani, O; Berti, E; Bonechi, L; D'Alessandro, R; Goto, Y; Hong, B; Itow, Y; Kasahara, K; Kim, MH; Menjo, H; Nakagawa, ; Ohashi, K; Sako, T; Sakurai, N; Sato, K; Seidl, R; Tanida, K; Torii, S; Tricomi, A

    JOURNAL OF INSTRUMENTATION   Vol. 16 ( 10 )   2021.10

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    Authorship:Corresponding author   Language:English   Publishing type:Research paper (scientific journal)   Publisher:Journal of Instrumentation  

    In the RHIC forward (RHICf) experiment, an operation with pp collisions was performed at √(s) = 510 GeV from 24-27 June 2017. The performances, energy and position resolutions, trigger efficiency, stability, and background during the operation, have been studied using data and simulations, which revealed that the requirements for production cross-section and transverse single-spin asymmetry measurements of very forward photons, π0s, and neutrons were satisfied. In this paper, we describe the details of these studies.

    DOI: 10.1088/1748-0221/16/10/P10027

    Open Access

    Web of Science

    Scopus

  3. Simulation study on the effects of diffractive collisions on the prediction of the observables in ultra-high-energy cosmic-ray experiments Invited Reviewed International journal Open Access

    Ohashi, K; Menjo, H; Itow, Y; Sako, T; Kasahara, K

    PROGRESS OF THEORETICAL AND EXPERIMENTAL PHYSICS   Vol. 2021 ( 3 )   2021.3

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:Progress of Theoretical and Experimental Physics  

    The mass composition of ultra-high-energy cosmic rays is important for understanding their origin. Owing to our limited knowledge of the hadronic interaction, the interpretations of the mass composition from observations include several open problems, such as the inconsistent interpretations of 〈Xmax〉 and 〈Xmaxμ〉. Furthermore, a large difference between the predictions exists in the hadronic interaction models. Diffractive collision is one of the proposed sources of the uncertainty. In this paper, we discuss the effect of the detailed characteristics of diffractive collisions on the observables of ultra-high-energy cosmic-ray experiments, focusing on three detailed characteristics. These are the cross-sectional fractions of different collision types, the diffractive-mass spectrum, and diffractive-mass-dependent particle production from the diffractive dissociation system. We demonstrate that the current level of uncertainty in the cross-sectional fraction can affect 〈Xmax〉 by 8.9 g/cm2 and 〈Xmaxμ〉 by 9.4 g/cm2, whereas the other details of diffractive collisions exhibit relatively minor effects.

    DOI: 10.1093/ptep/ptab013

    Open Access

    Web of Science

    Scopus

  4. Measurement of energy flow, cross section and average inelasticity of forward neutrons produced in √s=13 TeV proton-proton collisions with the LHCf Arm2 detector Reviewed International coauthorship International journal Open Access

    Adriani, O; Berti, E; Bonechi, L; Bongi, M; D'Alessandro, R; Detti, S; Haguenauer, M; Itow, Y; Kasahara, K; Menjo, H; Muraki, Y; Ohashi, K; Papini, P; Ricciarini, S; Sako, T; Sakurai, N; Sato, K; Tamura, T; Tiberio, A; Torii, S; Tricomi, A; Turner, WC; Ueno, M

    JOURNAL OF HIGH ENERGY PHYSICS   Vol. 2020 ( 7 )   2020.7

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:Journal of High Energy Physics  

    In this paper, we report the measurement of the energy flow, the cross section and the average inelasticity of forward neutrons (+ antineutrons) produced in s = 13 TeV proton-proton collisions. These quantities are obtained from the inclusive differential production cross section, measured using the LHCf Arm2 detector at the CERN Large Hadron Collider. The measurements are performed in six pseudorapidity regions: three of them (η > 10.75, 8.99 < η < 9.21 and 8.80 < η < 8.99), albeit with smaller acceptance and larger uncertainties, were already published in a previous work, whereas the remaining three (10.06 < η < 10.75, 9.65 < η < 10.06 and 8.65 < η < 8.80) are presented here for the first time. The analysis was carried out using a data set acquired in June 2015 with a corresponding integrated luminosity of 0.194 nb−1. Comparing the experimental measurements with the expectations of several hadronic interaction models used to simulate cosmic ray air showers, none of these generators resulted to have a satisfactory agreement in all the phase space selected for the analysis. The inclusive differential production cross section for η > 10.75 is not reproduced by any model, whereas the results still indicate a significant but less serious deviation at lower pseudorapidities. Depending on the pseudorapidity region, the generators showing the best overall agreement with data are either SIBYLL 2.3 or EPOS-LHC. Furthermore, apart from the most forward region, the derived energy flow and cross section distributions are best reproduced by EPOS-LHC. Finally, even if none of the models describe the elasticity distribution in a satisfactory way, the extracted average inelasticity is consistent with the QGSJET II-04 value, while most of the other generators give values that lie just outside the experimental uncertainties. [Figure not available: see fulltext.].

    DOI: 10.1007/JHEP07(2020)016

    Open Access

    Web of Science

    Scopus

  5. Transverse Single-Spin Asymmetry for Very Forward Neutral Pion Production in Polarized <i>p</i> plus <i>p</i> Collisions at √<i>s</i>=510 GeV Reviewed International coauthorship International journal Open Access

    Kim, MH; Adriani, O; Berti, E; Bonechi, L; D'Alessandro, R; Goto, Y; Hong, B; Itow, Y; Kasahara, K; Lee, JH; Ljubicic, T; Makino, Y; Menjo, H; Nakagawa, I; Ogawa, A; Park, JS; Sako, T; Sakurai, N; Sato, K; Seidl, R; Tanida, K; Torii, S; Tricomi, A; Ueno, M; Zhou, QD

    PHYSICAL REVIEW LETTERS   Vol. 124 ( 25 ) page: 252501   2020.6

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:Physical Review Letters  

    Transverse single-spin asymmetries of very forward neutral pions generated in polarized p+p collisions allow us to understand the production mechanism in terms of perturbative and nonperturbative strong interactions. During 2017, the RHICf Collaboration installed an electromagnetic calorimeter in the zero-degree region of the STAR detector at the Relativistic Heavy Ion Collider (RHIC) and measured neutral pions produced at pseudorapidity larger than 6 in polarized p+p collisions at s=510 GeV. The large nonzero asymmetries increasing both in longitudinal momentum fraction xF and transverse momentum pT have been observed at low transverse momentum pT<1 GeV/c for the first time, at this collision energy. The asymmetries show an approximate xF scaling in the pT region where nonperturbative processes are expected to dominate. A non-negligible contribution from soft processes may be necessary to explain the nonzero neutral pion asymmetries.

    DOI: 10.1103/PhysRevLett.124.252501

    Open Access

    Web of Science

    Scopus

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MISC 9

  1. Measurements of longitudinal and transverse momentum distributions for neutral pions in the forward-rapidity region with the LHCf detector Reviewed

    Adriani O., Berti E., Bonechi L., Bongi M., D'Alessandro R., Del Prete M., Haguenauer M., Itow Y., Iwata T., Kasahara K., Kawade K., Makino Y., Masuda K., Matsubayashi E., Menjo H., Mitsuka G., Muraki Y., Papini P., Perrot A. -L., Ricciarini S., Sako T., Sakurai N., Suzuki T., Tamura T., Tiberio A., Torii S., Tricomi A., Turner W. C., Ueno M., Zhou Q. D.

    PHYSICAL REVIEW D   Vol. 94 ( 3 )   2016.8

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  2. Measurement of very forward neutron energy spectra for 7 TeV proton-proton collisions at the Large Hadron Collider Reviewed

    Adriani O., Berti E., Bonechi L., Bongi M., Castellini G., D'Alessandro R., Del Prete M., Haguenauer M., Itow Y., Kasahara K., Kawade K., Makino Y., Masuda K., Matsubayashi E., Menjo H., Mitsuka G., Muraki Y., Okuno Y., Papini P., Perrot A. -L., Ricciarini S., Sako T., Sakurai N., Sugiura Y., Suzuki T., Tamura T., Tiberio A., Torii S., Tricomi A., Turner W. C., Zhou Q. D.

    PHYSICS LETTERS B   Vol. 750   page: 360-366   2015.11

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  3. Transverse-momentum distribution and nuclear modification factor for neutral pions in the forward-rapidity region in proton-lead collisions at root(NN)-N-S=5.02 TeV Reviewed

    Adriani O., Berti E., Bonechi L., Bongi M., Castellini G., D'Alessandro R., Del Prete M., Haguenauer M., Itow Y., Kasahara K., Kawade K., Makino Y., Masuda K., Matsubayashi E., Menjo H., Mitsuka G., Muraki Y., Papini P., Perrot A. -L., Pfeiffer D., Ricciarini S., Sako T., Sakurai N., Suzuki T., Tamura T., Tiberio A., Torii S., Tricomi A., Turner W. C.

    PHYSICAL REVIEW C   Vol. 89 ( 6 )   2014.6

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  4. The performance of the LHCf detector for hadronic showers Reviewed

    Kawade K., Adriani O., Bonechi L., Bongi M., Castellini G., D'Alessandro R., Del Prete M., Haguenauer M., Itow Y., Kasahara K., Makino Y., Masuda K., Matsubayashi E., Menjo H., Mitsuka G., Muraki Y., Papini P., Perrot A-L., Ricciarini S., Sako T., Sakurai N., Shimizu Y., Suzuki T., Tamura T., Torii S., Tricomi A., Turner W. C.

    JOURNAL OF INSTRUMENTATION   Vol. 9   2014.3

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  5. Forward photon energy spectrum at LHC 7 TeV p-p collisions measured by LHCf Reviewed

    Menjo H., Adriani O., Bongi M., Castellini G., D'Alessandro R., Fukatsu K., Haguenauer M., Itow Y., Kasahara K., Kawade K., Macina D., Mase T., Masuda K., Mitsuka G., Muraki Y., Nakai M., Noda K., Papini P., Perrot A. -L., Ricciarini S., Sako T., Shimizu Y., Suzuki K., Suzuki T., Taki K., Tamura T., Torri S., Tricomi A., Turner W. C.

    NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT   Vol. 692   page: 224-227   2012.11

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    Authorship:Lead author   Language:English  

    DOI: 10.1016/j.nima.2011.12.071

    Web of Science

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Presentations 40

  1. Study of cosmic-ray interaction using LHC

    2024.9.18 

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    Event date: 2024.9

    Language:Japanese   Presentation type:Symposium, workshop panel (nominated)  

    Country:Japan  

  2. Status and Prospects of the LHCf experiment Invited International coauthorship International conference

    Hiroaki Menjo for the LHCf Collaboration

    22nd International Symposium on Very High Energy Cosmic Ray Interactions (ISVHECRI 2024)  2024.7.9 

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    Event date: 2024.7

    Language:English   Presentation type:Oral presentation (invited, special)  

    Venue:Puerto Vallarta   Country:Mexico  

  3. Very forward hadron measurements with LHCf/RHICf detectors Invited International coauthorship International conference

    Hiroaki Menjo for LHCf/RHICf Collaborations

    3rd Forward Physics Facility Meeting  2021.10.26 

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    Event date: 2021.10

    Language:English   Presentation type:Oral presentation (invited, special)  

    Venue:Online   Country:Switzerland  

  4. Status and Prospects of the LHCf and RHICf experiments International coauthorship International conference

    Hiroaki Menjo for LHCf/RHICf Collaborations

    37th ICRC (International Cosmic Ray Conference)  2021.7.18 

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    Event date: 2021.7

    Language:English   Presentation type:Oral presentation (general)  

    Venue:Online   Country:Germany  

  5. Preparation status for proton-oxygen collision measurement by LHCf International coauthorship

    2025.3.19 

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    Event date: 2025.3

    Language:Japanese   Presentation type:Oral presentation (general)  

    Country:Japan  

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Research Project for Joint Research, Competitive Funding, etc. 2

  1. Cosmic ray interactions in the knee and the highet energy regions

    2021.4 - 2022.3

    ICRR Inter-University  Research Program 

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    Authorship:Principal investigator  Grant type:Competitive

    Grant amount:\143000 ( Direct Cost: \143000 )

  2. Neutrino search associated with astronominal transient events International coauthorship

    2021.4 - 2022.3

    ICRR Inter-University  Research Program 

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    Authorship:Principal investigator  Grant type:Competitive

    Grant amount:\100000 ( Direct Cost: \100000 )

KAKENHI (Grants-in-Aid for Scientific Research) 10

  1. Measurement of very forward particles at LHC proton-oxygen collisions International coauthorship

    Grant number:24K00660  2024.4 - 2027.3

    Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (B)

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    Authorship:Principal investigator  Grant type:Competitive

    Grant amount:\18460000 ( Direct Cost: \14200000 、 Indirect Cost:\4260000 )

  2. Study of high energy cosmic-ray interactions using LHC proton-Oxygen collisions International coauthorship

    Grant number:23KK0056  2023.9 - 2027.3

    Grants-in-Aid for Scientific Research  Fund for the Promotion of Joint International Research (International Collaborative Research)

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    Authorship:Principal investigator  Grant type:Competitive

    Grant amount:\20930000 ( Direct Cost: \16100000 、 Indirect Cost:\4830000 )

  3. Measurement of strange mesons at very forward region of LHC proton-proton collisions International coauthorship

    Grant number:20H01917  2020.4 - 2023.3

    Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (B)

    Menjo Hiroaki

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    Authorship:Principal investigator  Grant type:Competitive

    Grant amount:\17680000 ( Direct Cost: \13600000 、 Indirect Cost:\4080000 )

    An operation has been performed with proton-proton collisions at the center-of-mass collision energy of 13.6 TeV in September 2022. Thanks to upgrade of data-readout system and trigger logic, the data were collected more efficiently than that in the past operations, and 300 M event in total were obtained.
    Including a 2015 operation data, we obtained results of differential production cross-section of eta meson. We found that QGSJET II model reproduced the result well. The eta/pi0 ratio showed mostly constant on the meson energy, and it indicate that a universal process produces such eta meson production.

  4. Study of proton-pion interactions using proton-proton collisions at LHC and RHIC

    Grant number:16K17692  2016.4 - 2019.3

    Grants-in-Aid for Scientific Research  Grant-in-Aid for Young Scientists (B)

    Menjo Hiroaki, Zhou Quidong, Ohashi Ken, Adamczyk Leszek, Riehn Felix, Ostapchenko Sergey

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    Authorship:Principal investigator  Grant type:Competitive

    Grant amount:\3770000 ( Direct Cost: \2900000 、 Indirect Cost:\870000 )

    We have successfully formed the joint analysis group of two LHC experiments, LHCf and ATLAS, for this unique measurement of proton-pion interaction study using proton-proton collisions. To understanding each experiment before going to this measurement, a simpler analysis has been performed, which is for measurement of diffractive-collision contribution on the forward photon production. Diffractive collisions are one of the main processes of proton-proton collisions. In these events, few particle are produced in the central region of collisions. Selecting no charged particle detection in the ATLAS detector, we analyzed LHCf photon events. Analysis of proton-pion interaction measurement is on-going and we will publish the result soon.

  5. Research and elucidation of the origin of particle production in the very forward region of RHIC polarized proton collisions International coauthorship

    Grant number:21H04484  2021.4 - 2025.3

    Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (A)

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    Authorship:Coinvestigator(s)  Grant type:Competitive

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